In 1952, French motorcycle racing champion Georges Monneret leaving Paris, France for for Calais, where he was met with a crew who installed a pair of custom pontoons to scooter. It was an amphibious craft powered by a 1952 125cc Vespa Douglas. From there, Monneret went about crossing the famed English Channel aboard the waterborne scooter.
http://www.vintag.es/2018/01/in-1952-georges-monneret-built.html